Failed to submit application_to YARN : User dev cannot submit applications to queue root.dev(requested queuename is default)
org.apache.hadoop.security.AccessControlException: Permission denied: user=dev, access=EXECUTE, inode="/tmp":root:supergroup:drwx
hadoop hdfs关闭权限管理
hadoop3.x /tmp 需要 777 权限
hadoop3.x yarn 调度策略：Fair Scheduler（公平调度）根据linux登录名提交到队列
SCD缓慢变化维、SCD缓慢变化维问题
hive教程：启动hadoop、mysql、metastore，测试是否启动成功
spark3.0教程-SparkSQL：连接MySQL，写入数据
spark3.0教程-SparkSQL：mode()、SaveMode 保存模式
spark3.0教程-SparkSQL：write.json()保存json文件